When you remove one from the array, you should decrement the counter. Example Function: These index numbers are always integer numbers which start at 0. An associative array lets you create lists of key and value pairs, instead of just numbered values. Bash provides one-dimensional indexed and associative array variables. Dictionary / associative arrays / hash map are very useful data structures and they can be created in bash. Deleting Array Elements. You can assign values to arbitrary keys: $ If you agree with that, then you probably won't want to read about the "new" associative arrays that were added in version 4.0 of bash. Deleting an element from the array To delete an element from the array we need to know it's index or its key in the case of an associative array, and use the unset command. Unfortunately, bash and ksh declare associative arrays Any variable may be used as an indexed array; the declare builtin will explicitly declare an array. I avoided associative arrays in my suggestion, because I only have access to bash version 3.2.57(1)-release (x86_64-apple-darwin16) and it doesn't have associative arrays. Remove duplicate array elements. unset array[0] removes the element but still if I do echo ${array[0]} I get a null value moreover there are other ways of doing this but if an element of an array contains spaces like below array[0]='james young' array[1]='mary' array[2]='randy orton' but these also fail to do the job. There are the associative arrays and integer-indexed arrays. There is no maximum limit on the size of an array, nor any requirement that members be indexed or assigned contiguously. array=${array[@]:1} #removed the 1st … The bash man page has long had the following bug listed: "It's too big and too slow" (at the very bottom of the man page). They work quite similar as in python (and other languages, of course with fewer features :)). We will go over a few examples. Using unset() Function: The unset() function is used to remove element from the array. For insertion, we used assignment operator. dictionaries were added in bash version 4.0 and above. 6.7 Arrays. CAVEAT: Requires bash 4+ CAVEAT: List order may not stay the same. It should iterate over each defined name and run the command. It only works with a 1-element array of an empty string, not 2 elements. I even checked older bash and it's still wrong there; like you say set -x shows how it expands. Alternately, only increment the counter in the conditional code for when you dont remove and item. Similarly, we can use delete statement to remove an element from the array. In Bash, there are two types of arrays. So "if condition then incremement counter, else remove item at current position" Last edited by Trilby (2012-09-06 11:51:32) on April 28, 2010. @Michael: Crap, you're right. I guess I didn't test that comment before posting. I normally use ksh instead of bash (and it has had associative arrays since 1993). Arrays in Bash. Create a temporary associative array. This unset command takes the array key as input and removed that element from the array. I have no idea why you have two counters. Bash, however, includes the ability to create associative arrays, and it treats these arrays the same as any other array. This allows us to effectively remove array duplicates. Let's see an example: When setting associative array values and a duplicate assignment occurs, bash overwrites the key. To check the version of bash run following: Introduction to bash arrays and bash array operations. To access array elements, we use array_name[index] format. The unset function is used to destroy any other variable and same way use to delete any element of an array. Elements in arrays are frequently referred to by their index number, which is the position in which they reside in the array. Bash Associative Arrays by Mitch Frazier. 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